CN114603131B

CN114603131B - Preparation method of nano-silver sol

Info

Publication number: CN114603131B
Application number: CN202210216211.3A
Authority: CN
Inventors: 石峰; 孙少茹; 徐志华; 冯丹妮; 张梦婷; 张人尹; 方阿社; 张铁颖; 马铭泽
Original assignee: Shihezi University
Current assignee: Shihezi University
Priority date: 2022-03-07
Filing date: 2022-03-07
Publication date: 2022-11-18
Anticipated expiration: 2042-03-07
Also published as: CN114603131A

Abstract

The invention discloses a preparation method of nano-silver sol, which relates to the technical field of nano-metal materials, wherein a reducing agent is L-arabinose, the L-arabinose has the functions of reducing and protecting, and the L-arabinose can be adsorbed on the surface of formed nano-silver particles while playing the role of the reducing agent, so that the nano-silver sol with uniform particle size and good dispersibility is obtained, a protective agent is not required to be additionally added, and the preparation method is favorable for developing the application potential of the nano-silver sol in a wider field.

Description

Preparation method of nano-silver sol

Technical Field

The invention relates to the technical field of nano metal materials, in particular to a preparation method of nano silver sol.

Background

In recent years, metal nano materials show brand-new performance due to unique physicochemical properties, and have potential application value in wide fields. Among them, nano silver particles (forming a colloidal state in a solution is called nano silver sol, also called colloidal silver) are a new functional material, and show potential application value in many fields by their unique optical, electrical, catalytic, bacteriostatic and chemical reaction properties. The nano silver has high specific surface area and surface activity, and can be widely used as photoelectric materials, antibacterial agents, catalyst materials, low-temperature superconducting materials, biosensor materials and the like.

L-arabinose is a special five-carbon aldose in plants, widely exists in the nature as a basic composition unit of biopolymers such as hemicellulose, pectin and gum, and is mainly obtained by separating and extracting from plants such as beet pulp, corn bran, corn cob, wheat bran, bagasse and the like. Has good physicochemical properties and health function, and can be widely applied to various fields such as food, chemical industry, medicine, etc.

At present, the preparation method of nano silver mainly comprises a physical method, a chemical reduction method and a biological reduction method. Physical methods are generally expensive in production cost and large in energy consumption; the chemical method needs to introduce a large amount of organic reagents, which is easy to cause pollution, and toxic substances which are difficult to remove are remained in the synthesized silver nano material, which can influence the application of the silver nano material in the field of medicine. The biological reduction method is a new green reduction method developed in recent years, and comprises a microbial synthesis method and a plant reduction method. The novel method utilizes the extracting solution of natural organisms as a reducing agent and a protective agent to reduce silver ions in the solution into silver simple substances so as to generate silver nanoparticles, but the method is easily influenced by pH and has harsh preparation conditions.

Disclosure of Invention

The invention aims to prepare a preparation method of nano silver sol which is environment-friendly, has controllable reaction conditions and simple synthesis process, and takes L-arabinose as a green reducing agent and a stabilizing agent to prepare novel silver nano particles with good dispersity and uniform particle size. The method has the advantages of convenient preparation process and low cost, provides a new idea for supplementing and perfecting the nano silver synthesis method, and has practical significance.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a preparation method of nano-silver sol, wherein a reducing agent is L-arabinose.

Further, after mixing silver nitrate, L-arabinose and water, carrying out reduction reaction on the mixed solution, and adjusting the pH value of the mixed solution by using a sodium hydroxide solution to obtain the nano silver sol.

Further, the pH value of the mixed solution is adjusted until the reaction system has brown yellow of the colloidal silver.

Further, the mass percentage content of the L-arabinose in the mixed solution is 0.01-0.06%.

Further, the mass-to-volume ratio of the silver nitrate in the mixed solution is 0.1-0.18 mg/mL.

Further, the temperature of the reduction reaction is 70-165 ℃, the reduction reaction is carried out under the stirring condition, and the stirring speed is 220-700 r/min.

Further, the mixing process comprises the steps of:

mixing silver nitrate with part of water to obtain a silver nitrate aqueous solution;

mixing the L-arabinose with the rest water to obtain an L-arabinose aqueous solution;

and mixing the silver nitrate aqueous solution with the L-arabinose aqueous solution to obtain the mixed solution.

Further, the concentration of the silver nitrate in the silver nitrate aqueous solution is 0.1-0.18 mg/mL.

Furthermore, the mass percentage of the L-arabinose in the L-arabinose aqueous solution is 0.5 to 3.0 percent.

Further, the silver nitrate aqueous solution and the L-arabinose aqueous solution are mixed under the stirring condition, the rotating speed is 300-750 r/min, and the time is 10-60 min.

Further, the nano silver sol comprises nano silver particles and arabinose attached to the surfaces of the nano silver particles.

Further, the particle size of the nano silver sol in the nano silver sol is 50-80 nm.

The invention also provides application of the nano silver sol prepared by the preparation method in preparation of antibacterial materials.

The invention discloses the following technical effects:

the invention provides a method for preparing nano-silver sol by using a reduction method with L-arabinose as a reducing agent and a protective agent, wherein the L-arabinose can be adsorbed on the surface of formed nano-silver particles while playing the role of the reducing agent, the nano-silver sol with uniform particle size and good dispersibility can be obtained by avoiding the agglomeration of the nano-particles, the protective agent is not required to be additionally added, and compared with the method for preparing the nano-silver sol by using malic acid and glycyrrhizic acid as the reducing agent, the method has the advantages that the antibacterial effect is better, the size of an antibacterial ring is 24mm, and the development of the application potential of the nano-silver sol in wider fields is facilitated.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required in the embodiments will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a UV/VIS spectrum of the nano-silver sol prepared in example 1;

FIG. 2 is a transmission electron microscope image of the nano-silver sol prepared in example 1;

FIG. 3 is a distribution diagram of the particle size of nanoparticles in the nano-silver sol prepared in example 2;

FIG. 4 is a zeta potential diagram of nanoparticles in the nano-silver sol prepared in example 2;

FIG. 5 is a UV/Vis spectrum of the nano-silver sol prepared in example 3;

fig. 6 is a uv/vis spectrum of the nano silver sol prepared in example 4.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every intervening value, to the extent any stated value or intervening value in a stated range, and any other stated or intervening value in a stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

In the present invention, all the raw materials are commercially available products well known to those skilled in the art, and the water is preferably distilled water or ultrapure water, unless otherwise specified.

In the invention, the preparation method of the nano-silver sol comprises the following steps: mixing silver nitrate, L-arabinose and water, carrying out reduction reaction on the mixed solution, and adjusting the pH value of the mixed solution by using a sodium hydroxide solution to obtain the nano-silver sol.

In the invention, the pH value of the mixed solution is adjusted until the reaction system has brown yellow of the colloidal silver.

In the invention, the mass percentage of the L-arabinose in the mixed solution is 0.01-0.06%, and more preferably 0.03-0.04%. In the present invention, the mass-to-volume ratio of silver nitrate in the mixed solution is 0.1 to 0.18mg/mL, and more preferably 0.1mg/mL. In the invention, the mixed solution is preferably stirred at a rotation speed of 300-750 r/min, more preferably 350-700 r/min; the stirring time is preferably 10 to 60min, more preferably 10 to 40min.

According to the invention, the mixing container is preferably subjected to a cleaning treatment before the mixed solution is prepared so as to ensure the cleanliness of the container. In the present invention, the cleaning treatment is preferably performed in a manner of cleaning the container for mixing the silver nitrate aqueous solution, and thus, the detailed description thereof will not be repeated.

In the present invention, the temperature of the reduction reaction is 70 to 165 ℃, more preferably 75 to 165 ℃. The temperature of the reduction reaction is preferably the same as the temperature of the silver nitrate aqueous solution at the time of preparing the mixed solution. The invention limits the temperature of the reduction reaction within the range, and can obtain the nano silver sol with uniform particle size. The reduction reaction is carried out under stirring conditions, and the stirring speed is 220-700 r/min, and more preferably 250-600 r/min. In the invention, the reaction solution is changed from colorless to light yellow and then to brown yellow in the reduction reaction process, and when the reaction solution is changed to brown yellow, the reaction is continued for 5-10 min to finish the reaction. After the reduction reaction is finished, the reaction product is preferably sequentially cooled and filtered; the cooling method is not particularly limited, and a conventional cooling method can be adopted. In the present invention, the cooled product is preferably diluted before the filtration, the solvent for dilution is preferably double distilled water, and the volume of the solution after dilution is preferably the same as the total volume of the mixed solution. In the present invention, the pore size of the filtration membrane is preferably 0.22 to 0.45 μm, and more preferably 0.45 μm, and the nano silver sol having a large particle size generated by aggregation can be removed by filtration.

In the present invention, the mixing process comprises the steps of:

and mixing the silver nitrate aqueous solution with the L-arabinose aqueous solution to obtain the mixed solution. According to the invention, the raw materials can be uniformly mixed according to the step-by-step mixing mode, and the subsequent reaction is favorably carried out.

In the invention, the mass-to-volume ratio of the silver nitrate in the silver nitrate aqueous solution is 0.1-0.18 mg/mL. Still more preferably 0.1mg/mL. The invention has no special requirements on the mixing process for preparing the silver nitrate aqueous solution, as long as the silver nitrate aqueous solution can be uniformly mixed. The present invention preferably cleans the mixing vessel prior to mixing to ensure the cleanliness of the vessel. In the present invention, the cleaning treatment preferably includes washing, rinsing and drying in this order; the cleaning solution preferably comprises an aqueous solution of a detergent, an aqueous solution of a detergent powder or an aqueous solution of a washing powder, and the cleaning is preferably brushing. In the present invention, the rinsing solvent is preferably distilled water, and the number of rinsing is preferably 2 to 5, more preferably 3 to 4. In the present invention, the drying temperature is preferably 70 to 100 ℃, more preferably 80 to 90 ℃, and the time is preferably 120 to 240min, more preferably 150 to 200min.

In the invention, the mass percentage of the L-arabinose in the L-arabinose aqueous solution is 0.5 to 3.0 percent. More preferably 0.5 to 2.0%. The mixing process for preparing the L-arabinose aqueous solution is not particularly limited, as long as the L-arabinose aqueous solution can be uniformly mixed. The present invention preferably cleans the mixing vessel prior to mixing to ensure the cleanliness of the vessel. In the present invention, the cleaning treatment is preferably performed in a manner of cleaning the container for mixing the silver nitrate aqueous solution, and thus, the detailed description thereof will not be repeated.

In the invention, the silver nitrate aqueous solution and the L-arabinose aqueous solution are mixed under the stirring condition, the rotating speed is 300-750 r/min, and the time is 10-60 min.

In the present invention, the nano silver sol includes nano silver particles and L-arabinose attached to the surfaces of the nano silver particles.

In the invention, the particle size of the nano silver particles in the nano silver sol is 50-80 nm.

In the invention, the nano silver sol prepared by the preparation method is used for preparing antibacterial materials.

Example 1

The used utensils are brushed and cleaned by detergent, then the utensils are soaked and cleaned for three times by distilled water, and finally the utensils are dried for 3 hours at the temperature of 80 ℃ to obtain clean utensils;

mixing 1g of L-arabinose with 100mL of double distilled water to obtain an arabinose aqueous solution with the mass percentage of 1%;

mixing 4g of NaOH with 100mL of double distilled water to obtain a NaOH aqueous solution with the concentration of 1 mol/L;

adding 5mg of silver nitrate into 48.5mL of double distilled water, heating to 75 ℃ at the rotating speed of 250r/min, adding 1.5mL of 1-percent L-arabinose aqueous solution into 75 ℃ of silver nitrate aqueous solution, continuously stirring for 5min at the rotating speed of 250r/min, adding 0.014mL of 1mol/L NaOH aqueous solution, adjusting the pH value until the reaction system has brown yellow color of colloidal silver, and continuously stirring for 34min; obtaining a mixed solution;

stirring the mixed solution at 75 ℃ for 34min at 250r/min, changing the color of the reaction solution from colorless to stable brown yellow, continuing stirring for 5min, stopping heating and stirring, and cooling to room temperature; and diluting the cooled product to 50mL by using double distilled water, and filtering (the aperture of a filter membrane is 0.45 mu m) to obtain the nano silver sol.

The nano silver sol prepared in example 1 was analyzed by uv/vis light, and the uv/vis spectrum was shown in fig. 1. As can be seen from fig. 1, the peak of the plasmon resonance absorption peak (SPR) of the nano-silver sol prepared in example 1 was 436nm, and the peak shape of the SPR peak was narrow, which indicates that the nano-silver particles in the nano-silver sol prepared in example 1 had a good uniformity in particle size.

The nano silver sol prepared in example 1 was observed by transmission electron microscopy, and the transmission electron microscopy image is shown in fig. 2. As can be seen from fig. 2, the silver nanoparticles in the nano silver sol prepared in example 1 had good dispersibility and uniform particle size distribution, and the particle size of the obtained silver nanoparticles was about 80nm.

Example 2

adding 5mg of silver nitrate into 48mL of double distilled water, heating to 75 ℃ at the rotating speed of 300r/min, adding a 2mL 1L-arabinose aqueous solution into a 75 ℃ silver nitrate aqueous solution, continuously stirring for 5min at the rotating speed of 250r/min, adding 0.01mL 1mol/L NaOH aqueous solution, adjusting the pH value until the reaction system has brown yellow color of colloidal silver, and continuously stirring for 22min to obtain a mixed solution;

stirring the mixed solution at 75 ℃ for 250r/min for 22min, changing the color of the reaction solution into stable brown yellow, continuously stirring for 5min, stopping heating and stirring, and cooling to room temperature; and diluting the cooled product to 50mL by using double distilled water, and filtering (the aperture of a filter membrane is 0.45 mu m) to obtain the nano silver sol.

The particle size distribution of the nano silver sol prepared in example 2 was analyzed by a dynamic light scattering instrument, and the particle size distribution of the nano particles in the nano silver sol is shown in fig. 3. As can be seen from fig. 3, the nano silver sol in the nano silver sol prepared in example 2 had a particle size distribution in the range of 50 to 80m, and the particle size of the nano silver sol was mainly about 60 nm.

The surface potential of the nano silver sol prepared in example 2 was measured by a dynamic light scattering instrument, and a zeta potential map was obtained as shown in fig. 4. As is clear from FIG. 4, the zeta potential of the nano-silver sol prepared in example 2 was-26.7 mV, indicating that the nano-silver sol prepared in example 2 was in a stable colloidal state.

Example 3

The used utensil is cleaned by using detergent, then is wetted and washed for three times by using distilled water, and finally is dried for 3 hours at the temperature of 80 ℃ to obtain a clean utensil;

adding 5mg of silver nitrate into 48.5mL of double distilled water, heating to 120 ℃ at the rotation speed of 550r/min, adding 1.5mL of 1-L-arabinose aqueous solution into the 120 ℃ silver nitrate aqueous solution, continuously stirring for 5min at the rotation speed of 550r/min, adding 0.005mL of 1mol/L NaOH aqueous solution to adjust the pH value until the reaction system has a brown yellow color of colloidal silver, and continuously stirring for 10min to obtain a mixed solution;

stirring the mixed solution at 120 ℃ for 550r/min for 5min, changing the color of the reaction solution into stable brown yellow, continuing stirring for 10min, stopping heating and stirring, and cooling to room temperature; and diluting the cooled product to 50mL by using double distilled water, and filtering (the aperture of a filter membrane is 0.45 mu m) to obtain the nano silver sol.

As can be seen from fig. 5, the peak of the plasmon resonance absorption peak (SPR) of the nano-silver sol prepared in example 3 was 434nm, and the peak profile of the SPR peak was narrow, which indicates that the nano-silver particles in the nano-silver sol prepared in example 3 had good uniformity.

Example 4

adding 5mg of silver nitrate into 49mL of double distilled water, heating to 165 ℃ at the rotating speed of 400r/min, adding 1mL of L-arabinose aqueous solution to 165 ℃ of silver nitrate aqueous solution, continuously stirring for 5min at the rotating speed of 400r/min, adding 0.009mL of 1mol/L NaOH aqueous solution, adjusting the pH value until the reaction system has brown yellow of colloidal silver, and continuously stirring for 19min to obtain a mixed solution;

stirring the mixed solution at 165 ℃ for 400r/min for 5min, changing the color of the reaction solution into stable brown yellow, continuing stirring for 19min, stopping heating and stirring, and cooling to room temperature; and diluting the cooled product to 50mL by using double distilled water, and filtering (the aperture of a filter membrane is 0.45 mu m) to obtain the nano silver sol.

As can be seen from fig. 6, the peak of the plasmon resonance absorption peak (SPR) of the nano-silver sol prepared in example 4 was 439nm, and the peak profile of the SPR peak was narrow, which indicates that the nano-silver particles in the nano-silver sol prepared in example 4 had good uniformity.

And (3) comparison test: the used utensils are brushed and cleaned by detergent, then the utensils are soaked and cleaned for three times by distilled water, and finally the utensils are dried for 3 hours at the temperature of 80 ℃ to obtain clean utensils;

the following tests were carried out:

comparative example 1

5mg of silver nitrate was added to 48.5mL of double distilled water, and in a static state, 1.5mL1% L-arabinose aqueous solution was added to the silver nitrate aqueous solution at normal temperature, and the mixture was left to stand for a certain period of time.

The obtained reaction system has no change, and the brown yellow of the colloidal silver reaction system does not appear.

Comparative example 2

Adding 5mg silver nitrate into 48mL double distilled water, heating to 30 deg.C at 400r/min, adding 2mL 1-arabinose aqueous solution to silver nitrate aqueous solution at 30 deg.C, stirring at 400r/min for 5min, adding 0.01mL 1mol/L NaOH aqueous solution to adjust pH, and stirring for 7min to obtain mixed solution.

The obtained reaction system is gray, and the brown yellow of the colloidal silver reaction system is still in a solution state.

Comparative example 3

5mg of silver nitrate was added to 48mL of double distilled water, the mixture was heated to 300 ℃ at a rotation speed of 400r/min, a 2mL 1L-arabinose aqueous solution was added to the 300 ℃ silver nitrate aqueous solution, the mixture was stirred at a rotation speed of 400r/min for 5min, a 0.009mL 1mol/L NaOH aqueous solution was added to adjust the pH, and the mixture was stirred for 22min to obtain a mixed solution.

The obtained reaction system had a soil color, and solids were precipitated.

Comparative example 4

Adding 5mg of silver nitrate into 48mL of double distilled water, heating to 75 ℃ at a rotation speed of 250r/min, adding 2mL of 1-L-arabinose aqueous solution into 75 ℃ of silver nitrate aqueous solution, continuing to stir at a rotation speed of 250r/min for 5min, adding 0.025mL of 1mol/L NaOH aqueous solution, adjusting the pH, and continuing to stir for 22min to obtain a mixed solution.

The obtained reaction system is grayish white and slightly yellow, is in a solution state, and precipitates a solid after standing.

Comparative example 5

Adding 5mg of silver nitrate into 48mL of double distilled water, heating to 75 ℃ at a rotation speed of 250r/min, adding 2mL of 1-arabinose aqueous solution into 75 ℃ of silver nitrate aqueous solution, continuing to stir at a rotation speed of 250r/min for 5min, adding 0.002mL of 1mol/L NaOH aqueous solution, adjusting pH, and continuing to stir for 22min to obtain a mixed solution.

The reaction system obtained was slightly grayed and remained in the state of a solution.

The above-described embodiments are only intended to illustrate the preferred embodiments of the present invention, and not to limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A preparation method of nano silver sol is characterized in that silver nitrate is mixed with part of water to obtain silver nitrate water solution; mixing the L-arabinose with the rest water to obtain an L-arabinose aqueous solution; mixing the silver nitrate aqueous solution and the L-arabinose aqueous solution for 10-40 min to obtain a mixed solution, carrying out reduction reaction on the mixed solution at the temperature of 75-165 ℃, and adjusting the pH value of the mixed solution by using a sodium hydroxide solution until the reaction system has brown yellow of colloidal silver to obtain nano silver sol;

the mass percentage of the L-arabinose in the mixed solution is 0.01-0.06%.

2. The method according to claim 1, wherein the concentration of silver nitrate in the mixed solution is 0.1 to 0.18mg/mL.

3. The method according to claim 1, wherein the reduction reaction is carried out under stirring at a rotation speed of 220 to 700r/min.

4. The preparation method according to claim 1, wherein the mixing of the aqueous silver nitrate solution and the aqueous L-arabinose solution is performed under stirring at a rotation speed of 300 to 750r/min.

5. The preparation method according to claim 1, wherein the nano silver sol comprises nano silver particles and L-arabinose attached to the surfaces of the nano silver particles.

6. The method according to claim 5, wherein the nano silver particles in the nano silver sol have a particle size of 50 to 80nm.

7. Use of the nano silver sol prepared by the preparation method of any one of claims 1 to 6 in preparation of antibacterial materials.